The present invention relates generally to mechanism for producing panels of polymer tubing suitable for use in solar heat collection panels, heat exchangers, and other devices.
Solar heat collection panels and heat exchangers are used in a wide variety of applications and have a wide variety of geometries and designs for specific applications. Most often, heat exchangers are formed from a metal material such as copper, aluminum or stainless steel due to the favorable heat transfer characteristics that are displayed by such materials. Although metal heat exchanger designs work well for many applications, metals tend to be more expensive or more subject to corrosion than certain other materials, such as plastics. Thus, there are some applications where it is desirable to form a heat exchanger from lower cost polymer materials.
Solar heat collection panels have been used for a number of years to heat or preheat water and/or other fluids for a number of applications. One type of solar heat collection panel includes a series of riser tubes that extend in parallel between a pair of header pipes. The header pipes and risers can be formed from a wide variety of materials, but one class of heat exchangers use simple extruded plastic or elastomer tubing. When plastic tubing is used as the risers, adjacent tubes can be extruded, tack welded or supported together so that an array of side-by-side tubes forms a collection panel. A variety of plastics may be used to form the panels, although generally a dark, thermoplastic material is used. Such panels have been sold by FAFCO Inc. of Chico, Calif., and are described, for example, in U.S. Pat. No. 4,205,662.
As these existing solar panel designs work quite well, there are continuing efforts to develop new and improved methods and apparatuses for producing solar heat collection panels, heat exchangers, and other devices.